Rubber dam



(No Model.)

G. P. PITMAN.

' RUBBER DAM. N0.'484,046. Patented Oct. 11; 1892.

WITNESSES! M/VENTOH %V/ BY Y ll 1 M Q) fi A TTORNE Y3.

' NITED STATES PATENT OFFICE.

CHARLES P. PITMAN, OF FREEHOLD, NEW JERSEY.

RUBBER DAM.

SPECIFICATION forming part of Letters Patent No. 484,046, dated October 11, 1892.

Application filed April 14, 1392.

through between the teeth, and which may also be used for spreading the teeth.

In using a dentists rubber dam two or more perforations are made into the rubber dam to receive the adjoining teeth preparatory to filling. The portion of the dam which lies between the teeth is necessarily very narrow and weak and the saliva will therefore readily force its way toward the crown, which is, of course, very objectionable. It is the object of my invention to so construct this portion of the dam thata tight joint will be produced which Will effectively exclude moisture while the dentist is preparing cavities and treating or filling the teeth.

In the accompanying drawings, Figure 1 is a perspective view of the dam, showing it in use. Fig. 2 is a top View of the dam. Fig. 3 is a cross-section thereof. Figs. 4 and 5 are corresponding views of a modification, and Figs. 6 and 7 corresponding views of a further modification.

The letter (It represents the rubber dam proper, being a sheet of thin rubber, as usual. Upon either one or both of the faces of this rubber dam I form upwardly-projecting elastic bridges or ribs a, either by molding or Serial No. 429,097. (No model.)

otherwise. The bridges a may have various forms and dimensions, according to the particular uses to which they are to be put. Thus in Figs. 2 and 3 the bridge consists of aplain straight elastic strip, in Figs. 4 and 5 the strip a is grooved, while in Figs. 6 and 7 two curved diverging strips 0/ are used. In this way other modifications will suggest themselves.

In use two openings a are punched into the dam to the right and left of the bridge. The dam is spread and drawn over and between the teeth A, Fig. 1, with the bridge resting against the gum. In stretching the dam the bridge will have become distended and reduced in thickness, and after the dam is in place the bridge or rib in contracting will crowd against the teeth and produce a very tight packing. Thus the teeth are kept dry and the gum is crowded away. That this is highly desirable will be apparent to every dentist.

Beside the ordinary use of the dam it may also be employed to spread a pair of adjoining teeth, as will be readily understood.

What I claim is- 1. A dentists rubber dam provided with a raised elastic bridge, substantially as specified.

2. A dentists rubber dam provided with a raised elastic bridge and perforations at the sides of the bridge, substantially as specified.

CHARLES P. PITMAN.

Witnesses:

F. v. BRIESEN, A. J ONGHMANS. 

